Secular Stagnation – a prolonged period in which satisfactory growth can only be achieved by unsustainable financial conditions –may be the defining macro-economic challenge of our times. The concept of “Secular Stagnation” originally formulated by the eminent Depression-era economist Alvin Hansen, has experienced a revival since my November 2013 speech on the topic.

Lawrence H. Summers is the Charles W. Eliot University Professor and President Emeritus at Harvard University. He served as the 71st Secretary of the Treasury for President Clinton and the Director of the National Economic Council for President Obama.